Example embodiments of the inventive concepts relate to semiconductor devices, and in particular, to semiconductor memory devices having a vertical memory cell structure.
Higher integration of semiconductor devices is desired to satisfy consumer demands for high performance at low prices. In the case of semiconductor memory devices, the integration density of the device is an important factor in determining the price thereof. In the case of conventional two-dimensional semiconductor memory devices, since their integration is mainly determined by the area occupied by a unit memory cell, integration is greatly influenced by the level of a fine pattern forming technology. However, the extremely expensive process equipment needed to increase pattern fineness sets a practical limitation on increasing integration for two-dimensional semiconductor memory devices.